Animal models of cocaine use: importance of social context and co-use.

Cocaine-use disorders (CUDs) continue to be a major public health problem that requires effective treatments. Despite decades of preclinical research, there are no FDA-approved pharmacotherapies for cocaine use. While there are numerous potential reasons why no efficacious treatments have been identified or approved for cocaine use, we discuss two possible reasons in this review: the low number of studies incorporating social variables and the overlooking of the clinical reality of polysubstance use. These variables impact drug use across the substance-use cycle, including vulnerability, maintenance, and treatment. Recent preclinical and clinical data suggest that cocaine users who engage in polysubstance use should be viewed as a distinct and more prevalent population who require unique behavioral and pharmacological approaches to reduce cocaine use. Therefore, to understand the neurobiology and eventual treatments for CUDs, both variables should be included in animal models.